Getting multiple highest values using Cell Statistics in ArcGIS Pro

You can use RasterToNumPyArray to convert your rasters to numpy arrays and then use Numpy to extract statistics from the arrays. In this example, I extract the median value from each of the 12 arrays, add them to a dictionary, and pick out the top 4 items using Counter.

import numpy as np
from collections import Counter

# Generate some sample numpy array data
datadict = {}
months = ["jan","feb","mar","apr","may","jun","jul","aug","sep","oct","nov","dec"]

for m in months:
    datadict[m] = np.random.randint(255, size=(4, 4))

# Generate a dict with variable name key and median value
d = {k:np.median(v) for k,v in datadict.items()}

# Returns the top 4 items in dict
vals = Counter(d).most_common(4) 
print(vals)

---

[('oct', 169.0), ('jun', 158.5), ('mar', 134.5), ('apr', 134.0)]